Malaysian Journal of Analytical Sciences Vol 22 No 5 (2018):  794 - 806

DOI: 10.17576/mjas-2018-2205-07




Bioaccessibility Assessment of 232Th  and 238U from Lanthanide Concentrate and Water Leach Purification Residue in Malaysia


(Penilaian Bio-Kebolehcapaian bagi 232Th  Dan 238U dalam Lantanida Pekat dan Residu Permurnian Larut Resap Air di Malaysia)


Nur Shahidah Abdul Rashid1*, Um Wooyong1, Yasmin Mohd Idris Perama2, Amran Ab.Majid2, Khoo Kok Siong2


1Division of Advanced Nuclear Engineering,

Pohang University of Science and Technology, Pohang, Republic of Korea

2School of Applied Physics, Faculty of Science and Technology,

Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia


*Corresponding Author :



Received: 28 September 2017; Accepted: 11 August 2018




The aim of this case study was to estimate the bioaccessibility of 232Th and 238U from lanthanide concentrate (LC) and water leach purification (WLP) residue of Lynas Advanced Materials Plant by analysing the solubility of these radionuclides in synthetic gastrointestinal fluids. A DIN in vitro bioaccessibility method was applied to determine the targeted radionuclides from the LC and WLP residue, which were further evaluated through inductively coupled plasma mass spectrometry. 232Th and 238U concentrations in the gastrointestinal fluids portrayed the maximum amount of contaminants that were potentially available for intestinal absorption and transfer into the blood. The maximum concentrations of 232Th in the LC and WLP residue were 0.1410 ± 0.0331 mg kg-1 and 0.1621 ± 0.1190 mg kg-1, respectively. As for 238U in the LC and WLP residue during the intestinal phase for high-risk cases, the maximum concentrations were 0.0558 ± 0.0164 mg kg-1 and 0.0480 ± 0.0213 mg kg-1, respectively. The maximum bioaccessibility of 232Th and 238U was 0.14 % and 0.93 %, respectively. Based on the assessment, the committed equivalent dose and committed effective dose of 232Th and 238U were below the United Nations Scientific Committee on the Effects of Atomic Radiation reference values. Overall, the DIN in vitro bioaccessibility method is feasible to estimate the solubility of 232Th and 238U from LC and WLP residue, and is also useful for monitoring and risk assessment purposes for environmental, health, and contaminated samples.


Keywords:  bioaccessibility, thorium, uranium, lanthanide concentrate, water leach purification



Tujuan kajian ini ialah mengkaji bio-kebolehcapaian 232Th dan 238U dari sampel lantanida pekat (LC) dan residu pemurnian larut resap air (WLP) yang terdapat di loji bahan termaju Lynas, dengan kaedah penentuan melalui kebolehlarutan radionuklid tersebut di dalam cecair sintetik gastrousus. Sampel LC dan residu WLP telah menjalani teknik bio-kebolehcapaian in vitro DIN, dan seterusnya sampel dianalisis menggunakan Spektrometer Jisim-Gandingan Plasma Teraruh. Kepekatan 232Th dan 238U dalam cecair gastrousus mewakili jumlah maksimum pencemaran radionuklid yang berpotensi diserap ke dalam badan melalui usus dan berpindah ke dalam darah. Kepekatan maksimum 232Th dalam LC dan residu WLP ialah 0.1410 ± 0.0331 mg kg-1 dan 0.1621 ± 0.1190 mg kg-1. Bagi 238U dalam LC dan residu WLP semasa fasa usus bagi kes berisiko tinggi ialah 0.0558 ± 0.0164 mg kg-1 dan 0.0480 ± 0.0213 mg kg-1. Nilai bio-kebolehcapaian maksimum bagi 232Th  dan 238U ialah 0.14% dan 0.93%. Berdasarkan kajian, dos komited setara dan dos komited berkesan bagi 232Th dan 238U adalah di bawah nilai rujukan United Nations Scientific Committee on the Effects of Atomic Radiation. Kesimpulannya, teknik bio-kebolehcapaian in vitro DIN sangat berguna untuk menganggar kelarutan 232Th dan 238U bagi tujuan pemantauan berterusan dan penilaian risiko terhadap alam sekitar, kesihatan manusia, dan sampel tercemar.



Kata kunci:  bio-kebolehcapaian, torium, uranium, lantanida pekat, permurnian larut resap



1.       Charalampides, G. and Vatalis, K. I. (2015). Global production estimation of rare earth elements and their environmental impacts on soils. Journal of Geoscience and Environment Protection, 3(8): 66.

2.       Schmidt, G. (2013). Description and critical environmental evaluation of the REE refining plant LAMP near Kuantan/Malaysia. Radiological and non-radiological environmental consequences of the plant's operation and its wastes.

3.       O'Brien, R., S. and Cooper, M. B. (1998). Technologically enhanced naturally occurring radioactive material (NORM): Pathway analysis and radiological impact. Applied Radiation and Isotopes. 49(3):227-239.

4.       Sowby,  F., D.  (1965).  Radiation protection. Canadian Medical Association Journal, 92(19): 1039.

5.       World Health Organization (2012). Ionizing  radiation,  health effects  and  protective  measures. Access online [Access online 20 April 2016].

6.       Chaney, R. L., Mielke, H.W. and Sterrett, S. B. (1989). Speciation, mobility and bioavailability of soil lead. Environmental Geochemistry Health, 11: 105-129.

7.       Calabrese, E. J. and Stanek, E. J. (1994). Soil ingest ion issues and recommendations. Journal of Environmental Science & Health Part A, 29(3): 517-530.

8.       Omar, N. A., Praveena, S., Mohd, A., Ahmad, Z. and Hashim, Z. (2013). Bioavailability of heavy metal in rice using in vitro digestion model. International Food Research Journal, 20(6): 2979-2985.

9.       Oomen, A. G., Rompelberg, C. J. M., Bruil, M. A., Dobbe, C. J. G., Pereboom, D. P. K. H. and Sips, A. J. A. M. (2003). Development of an in vitro digestion model for estimating the bioaccessibility of soil contaminants. Archives of Environmental Contamination and Toxicology, 44(3): 0281-0287.

10.    Monachese, M., Burton, J. P. and Reid, G. (2012). Bioremediation and tolerance of humans to heavy metals through microbial processes: A potential role for probiotics. Applied and Environmental Microbiology, 78(18): 6397-6404.

11.    Al-Jundi, J., Werner, E., Roth, P., Höllriegl, V., Wendler, I. and Schramel, P. (2004). Thorium and uranium contents in human urine: Influence of age and residential area. Journal of Environmental Radioactivity, 71(1): 61-70.

12.    Van, D., W., Tom, R., Oomen, A., G., Wragg, J., Cave, Mark, Minekus, Mans, Hack, Alfons and Klinck, B. (2007). Comparison of five in vitro digestion models to in vivo experimental results: Lead bioaccessibility in the human gastrointestinal tract. Journal of Environmental Science and Health Part A, 42(9): 1203-1211.

13.    Kolo, M. T., Aziz, Siti, A. A., Khandaker, M., Uddin, A., Khandoker and Amin, Y. M. (2015). Evaluation of radiological risks due to natural radioactivity around Lynas Advanced Material Plant environment, Kuantan, Pahang, Malaysia. Environmental Science and Pollution Research, 22(17): 13127-13136.

14.    Wragg, J. and Cave, M. In-vitro methods for the measurement of the oral bioaccessibility of selected metals and metalloids in soils: A critical review. R&D Technical Report P5-062/TR/01 Environment Agency: pp. 1-28.

15.    National Toxics Network (2012). Rare earth and radioactive waste a preliminary waste stream assessment of the Lynas Advanced Materials Plant, Gebeng, Malaysia.

16.    Pasquale, V., Verdoya, M. and Chiozzi, P. (2001). Radioactive heat generation and its thermal effects in the Alps–Apennines boundary zone. Tectonophysics, 331(3): 269-283.

17.    Guo, P., Duan, T., Song, X., Xu, J. and Chen, H. (2008). Effects of soil pH and organic matter on distribution of thorium fractions in soil contaminated by rare-earth industries.  Talanta, 77(2): 624-627.

18.    International Atomic Energy Agency (2011). Radiation protection and NORM residue management in the production of rare earths from thorium containing minerals. Safety Reports Series No. 68.

19.    Langmuir, D. and Herman, J. S. (1980). The mobility of thorium in natural waters at low temperatures. Geochimica et Cosmochimica Acta, 44(11):1753-1766.

20.    Platford, R. F. and Joshi, S. R. (1989). Radionuclide partitioning across Great Lakes natural interfaces. Environmental Geology and Water Sciences, 14(3):183-186.

21.    International Commission on Radiological Protection (2012). ICRP Publication 119: Compendium of Dose Coefficients Based On ICRP Publication 60. Annal ICRP, 42(4): 2013.

22.    Johnson, J. R. and Lamothe, E. S. (1989). A review of the dietary uptake of Th. Health Physics, 56(2): 165-168.

23.    United  States  Environmental  Protection  Agency (2015).  Radionuclide basics:  Uranium. Access from [Access online 11 Jan 2018].

24.    Hooda, P. S., Henry, C. J. K., Seyoum, T. A., Armstrong, L., D. M. and Fowler, M. B. (2004). The potential impact of soil ingestion on human mineral nutrition. Science of the Total Environment, 333(1): 75-87.

25.    Bondietti, E.A. (1974). Adsorption of U (+ 4) and Th (+ 4) by soil colloids. In Agronomy Abstracts, 23.

26.    Guo, P., Duan, T., Song, X. and Chen, H. (2007). Evaluation of a sequential extraction for the speciation of thorium in soils from Baotou area, Inner Mongolia. Talanta, 71(2):778-783.

27.    Reiller, P., Moulin, V., Casanova, F. and Dautel, C. (2002). Retention behaviour of humic substances onto mineral surfaces and consequences upon thorium(IV) mobility: Case of iron oxides. Applied Geochemistry, 17(12): 1551-1562.

28.    Rand, M., H., Mompean, F., J., Perrone, J. and Illemassène, M. (2008). Chemical thermodynamics of thorium. OECD Publishing, 11: 1-393

29.    Oliver, D. P., McLaughlin, M. J., Naidu, R., Smith, L. H., Maynard, E. J. and Calder, I. C. (1999). Measuring Pb bioavailability from household dusts using an in vitro model. Environmental Science & Technology, 33(24): 4434-4439.

30.    Golev, A., Scott, M., Erskine, P. D., Ali, S. H. and Ballantyne, G. R. (2014). Rare earths supply chains: Current status, constraints and opportunities. Resources Policy. 41: 52-59.

31.    Adams, W. H., Buchholz, J. R., Christenson, C. W., Johnson, G. L. and Fowler, E. B. (1974). Studies of plutonium, americium, and uranium in environmental matrices: Los Alamos Scientific Lab., North Mexico.

32.    Träber, S. C., Höllriegl, V., Li, W. B., Czeslik, U., Rühm, W., Oeh, U. and Michalke, B. (2014). Estimating the absorption of soil-derived uranium in humans. Environmental Science & Technology, 48(24): 14721-14727.

33.    Rashid, N. S. A., Sarmani, S., Majid, A. A., Mohamed, F. and Siong, K. K. (2015). Solubility of 238U radionuclide from various types of soil in synthetic gastrointestinal fluids using “USP in vitro” digestion method. Proceedings of the Nuclear Science, Technology, and Engineering Conference 2014 (NuSTEC2014).

34.    Agency for Toxic Substances and Disease Registry (1990). Public health statement for Thorium. Access from (21 January 2018).

35.    Agency for Toxic Substances and Disease Registry (1999). Toxicological profile: Uranium. Access from (21 January 2018).

36.    Jacob, P., Pröhl, G., Schneider, K. and Voß, J. U. (1997). Machbarkeitsstudie zur Verknüpfung der Bewertung radiologischer und chemisch-toxischer  Wirkungen  von  Altlasten: Inst.  für  Strahlenschutz.

37.    World Health Organization (1998). Guidelines for drinking-water quality, Second edition, Addendum to Volume 2: Health Criteria and Other Supporting Information, WHO/EOS/98.1, Geneva 1998: pp. 283.

38.    World  Health  Organization.  (2003).  Guidelines  for  Drinking  Water  Quality,  Third  edition. Volume 1 – Recommendations Incorporating first and second addenda: pp. 1-668.

39.    Konietzka, R., Dieter, H. H. and Voss, J. U. (2005). Vorschlag für einen gesundheitlichen Leitwert für Uran in Trinkwasser. Umweltmed Forsch Prax, 10(2):133-143.

40.    Oomen, A., G., Hack, A., Minekus, M., Zeijdner, E., Cornelis, C., Schoeters, G. and Rompelberg, C., J., M. (2002). Comparison of five in vitro digestion models to study the bioaccessibility of soil contaminants. Environmental Science & Technology, 36(15): 3326-3334.

41.    Jadán, P., Carlos, C., P., Marie, J., Devesa, V. and Vélez, D. (2016). Influence of physiological gastrointestinal parameters on the bioaccessibility of mercury and selenium from swordfish. Journal of Agricultural and Food Chemistry, 64(3): 690-698.

42.    Vázquez, M., Calatayud, M., Piedra, C. J., Chiocchetti, G. M., Vélez, D. and Devesa, V. (2015). Toxic trace elements at gastrointestinal level. Food and Chemical Toxicology. 86:163-175.

43.    Morrow, P. E., Gibb, F. R. and Beiter, H. D. (1972). Inhalation studies of uranium trioxide. Health Physics, 23(3): 273-280.

44.    Leggett, R. W. and Harrison, J. D. (1995). Fractional absorption of ingested uranium in humans. Health Physics, 68(4): 484-498.

45.    International Atomic Energy Agency (1999). Assessment for doses to the public from ingested radionuclides. IAEA Publishing, Safety Reports Series No. 14.

46.    United Nations Scientific Committee on the Effects of Atomic Radiation (2000). Sources and effects of ionizing radiation: sources. United Nations Publications, 1: 1-17.


Previous                    Content                    Next